Performance Dynamics Reviewed: EX Coupe

gbae007 · 06-25-2006, 02:32 AM

It has been about a month now that I've had the new EX Coupe 5MT. To preface, I'm not a tracking-going driver but I'm an avid "driving enthusiast" and consider myself a strong driver on the backroad twisties.

I've been taking weekend drives to get more intimate with the EX's handling, braking and road holding dynamics and this is a review of those areas, based on my experiences within the past 4 weeks.

UNDERSTEER
Driving a front-drive car, understeer is always a big consideration.

Fortunately, it is easily tempered by judicious use of the throttle and is a surprise given the front-biased weight distribution. (60/40; FR/RR). Understeer gets more apparent at low speed, sharper turns than say, a high-speed sweeper.

I wouldn't go far as saying that I can induce meaninful oversteer midcorner, but I have been able to rotate the car via left-foot braking and lift-throttle yaw at speed.

I haven't driven the Si, but I know that the spring rates, damping rates and roll-rate is increased relative to the EX (which in-turn, is more aggressive than the Civic Sedan.) In particular, based on Shawn Church's review from TOV, the Si's rear roll-bar has a relative 4xx% increase in stiffness than the EX. Still, I'm surprised than the EX handles and communicates road-feedback as with as it does, despite these setbacks.

HANDLING DYNAMICS
The stock configuration is more set up for a balance of comfort and performance than aggressive driving. The car simply does not like rapid direction changes. There is too much body roll, the rear starts to feel unsettled in a slalom situation and there is too much brake dive & acceleration sqaut.

I appreciate the ground clearance but I would gladly trade 1 to 1.5 inches of that to address the areas above.

The upside is that the low weight of the car allows you to "throw" the car into a corner at speeds faster than the laws of physics prescribe, only to pull out of a four-wheeled drift with some throttle-action.

BRAKES
Surprisingly capable. The have a sensitive initial bite and becomes easier to modulate after that initial bite. Strong braking throughout but noticeable brake fade exists in high-speed and downhill driving. At one point, I was driving on a road which twists downhill for about 5 miles and ends in a 100+ mph straight stretch. At the end of the run which concludes with a 100 - 0 mph run, I got out of my car to find the front brakes growing bright red. Most research I've done suggests that rotor surfaces must exceed 1300 deg F for this to happen.

On the bright side, despite the fade that occasionally creeps up in intense driving conditions, the brake pressure on the pedal remains consistant even when the rotors are operating at temperatures that should boil the brake fluid over.

THE NEXT STEP
I feel like I have a good idea of how the car handles - enough to starting thinking about addressing the dynamic weaknesses of the car. They are as follows:

[sway-bars]
Much stiffer roll-bars, especially in the rear. I hope to drive drive an Si for reference and if that doesn't prove to be aggressive enough (I suspect not,) then I will look to the aftermarket. I have only seen the Progress rear sway to date, and I wouldn't get that unless I had a front sway to keep that balance in check. The Progress rear sway is even stiffer than the Si's.

[dampers]
More than anything else, the dampers are the performance bottleneck in the EX suspension system. They are simply under-damped because the OEM emphasis is on comfort and not performance. The result is vagueness and sluggish manners. It also creates the sensation of floating, and not a firm contact with the road.

[springs]
I wish I knew the spring rates for all of the springs out there in the aftermarket for the EX coupe. Most times, manufacturers just list the drop in height. This is good if you want it just for look, but I know that spring rates can really define how the car feels. I need the numbers!

Anyway, once I do more reseach, I want to lower the car 1.0 to 1.5 inches to allow the use of a stiff spring rate.

That's it for now. This review isn't so much of a review, but me thinking out loud and getting my thoughts on paper, er the web.

Feel free to comment or ask question if you have them.

**webby** · 06-25-2006, 04:33 PM

wow that's a nice write up. Do you ever get into autox stuff at all? If you've never taken a stab at it, you may really enjoy doing some at some meets/weekend get togethers. As far as brake fade - I know a few members have already updated their pads to hawk or other brands which they said had a significant improvement in performance and brake fade issues. - less brake dust as well with some brands.

the spring rates can be seen below as far as helping you out a bit.
SI spring rates:
Front 200 lbs. / inch
Rear 230 lbs. / inch

This means that the DX, LX, and EX Coupe rates are approximately:
Front 170~175 lbs. / inch
Rear 200 ~ 205 lbs. / inch

This is taking into account the Si front rates are listed by Honda as being 17-18% stiffer and the rears are 14-15% stiffer than regular Coupes.

And obviously there is the ability to swap out the SI sway bars as well which are much thicker.

again - nice writeup.

aodmisery · 06-25-2006, 05:42 PM

dont know if your interested or if it fits on an ex but i got the stock si's suspension for sale 200 plus shipping.

P.s. this is my 100th post!! so what do i win!!

gbae007 · 06-25-2006, 06:34 PM

Quote:

Originally Posted by aodmisery

dont know if your interested or if it fits on an ex but i got the stock si's suspension for sale 200 plus shipping.

P.s. this is my 100th post!! so what do i win!!

I sent you a PM.

Regarding fitment, I believe everything fits between the EX and Si. For now, even if better pieces come out of the aftermarket, I want to swap my suspension out for the Si's. It seems too early in the 8th gen life cycle to put too much focus on aftermarket parts. Si's suspension is proven and I know it works.

All else equal, an EX with the Si's suspension will theoretically out handle the Si with OEM suspension because the EX is lighter by a couple hundred pounds or so. I don't have the LDS that Si's do, but that's another issue entirely.

**webby** · 06-25-2006, 06:37 PM

Quote:

Originally Posted by aodmisery

dont know if your interested or if it fits on an ex but i got the stock si's suspension for sale 200 plus shipping.

P.s. this is my 100th post!! so what do i win!!

gbae007 · 06-25-2006, 06:44 PM

Quote:

Originally Posted by webby

wow that's a nice write up. Do you ever get into autox stuff at all? If you've never taken a stab at it, you may really enjoy doing some at some meets/weekend get togethers. As far as brake fade - I know a few members have already updated their pads to hawk or other brands which they said had a significant improvement in performance and brake fade issues. - less brake dust as well with some brands.

the spring rates can be seen below as far as helping you out a bit.
SI spring rates:
Front 200 lbs. / inch
Rear 230 lbs. / inch

This means that the DX, LX, and EX Coupe rates are approximately:
Front 170~175 lbs. / inch
Rear 200 ~ 205 lbs. / inch

This is taking into account the Si front rates are listed by Honda as being 17-18% stiffer and the rears are 14-15% stiffer than regular Coupes.

And obviously there is the ability to swap out the SI sway bars as well which are much thicker.

again - nice writeup.

Thanks Webby. Do you know if there is a relative ride height drop going from the EX to Si springs?

I also wanted to point out that the EX is lighter by a small margin vs the Si, so the stiffer spring rate in the Si's isn't a completely linear % increase when used on the EX.

**webby** · 06-25-2006, 07:39 PM

Quote:

Originally Posted by gbae007

Thanks Webby. Do you know if there is a relative ride height drop going from the EX to Si springs?

I also wanted to point out that the EX is lighter by a small margin vs the Si, so the stiffer spring rate in the Si's isn't a completely linear % increase when used on the EX.

yeah - the ex is going to be a ligher vehicle compared to the SI. The si outweighs the EX due to the k20 engine as well as the limited slip differential, larger sways, (and I can't find the thread but somewhere someone weighed the EX seats compared to the SI seats and the si seats were heavier - if I remember right), etc.

ex 2701 manual weight
si 2877 manual weight

I don't know about ride height change going from ex to si springs only. I know a few members have bought the SI springs - they might be of help.

kenchan · 06-26-2006, 12:56 AM

i have a sedan, but i can surely agree to the 'floating' feeling you described.

the rear toe is set too mildly as if it's already at zero toe for tire wear
and fuel economy reasons... the rear wanders a tad when one side of
the car goes over a bump. this unsettling feel was apparent on not
only my EX sedan, but on other 06 civics.

When i do finally lower the ride down the road, i would set the rear
toe to about 0.10 to 0.12 degrees each side. this should minimize
the rear floating/shifting feel.

anyone know the factory rear toe setting? thanks.

iVTEC · 06-26-2006, 01:31 AM

I'd recommend purchasing 17" wheels with 215/45-17 tires and the Si front and rear sway bars before doing anything with the springs. It might just give you what you're looking for without having to sacrifice too much ride comfort by going with stiffer springs. The vagueness that you attribute to the dampers can also be caused by the flexible tire sidewalls and the relatively flimsy sway bars.

Check this out:

Si Front & Rear Sways on an EX Sedan

iVTEC · 06-26-2006, 02:04 AM

Or instead of upsizing the wheel size, you might consider just getting wider, lower profile tires (225/50-16) and keeping the stock rims. You might run into problems with the sidewalls bulging out though, since the stock rims are only six or six and a half inches wide.

jdm8thgen · 06-26-2006, 03:05 AM

Quote:

Originally Posted by iVTEC

I'd recommend purchasing 17" wheels with 215/45-17 tires and the Si front and rear sway bars before doing anything with the springs. It might just give you what you're looking for without having to sacrifice too much ride comfort by going with stiffer springs. The vagueness that you attribute to the dampers can also be caused by the flexible tire sidewalls and the relatively flimsy sway bars.

Check this out:

Si Front & Rear Sways on an EX Sedan

just upgrade the rear sway bar with the si one. adding the front too will just make the car push more in the turns rather than rotate.

GlennS · 06-26-2006, 01:39 PM

Okay, I've got a question that I can't find an answer to:

What are the HFP springs and dampers rated at?

There are HFP kits ($600 at College Hills) for the Si, the coupe and the sedan.
I've got a sedan, and I'm wondering how stiff (harsher ride) the HFP springs and dampers would be?

Sounds like an Si rear roll bar on the sedan would be a good move.
Si Front & Rear Sways on an EX Sedan

gbae007 · 06-26-2006, 02:29 PM

Quote:

Originally Posted by iVTEC

I'd recommend purchasing 17" wheels with 215/45-17 tires and the Si front and rear sway bars before doing anything with the springs. It might just give you what you're looking for without having to sacrifice too much ride comfort by going with stiffer springs. The vagueness that you attribute to the dampers can also be caused by the flexible tire sidewalls and the relatively flimsy sway bars.

Check this out:

Si Front & Rear Sways on an EX Sedan

This is a good suggestion - I was thinking of sways before the springs, anyway.

Regarding the tires, 225 would not safely fit on a 6.5 inch wide rim. (That's the EX 16" rim size.)

gbae007 · 06-26-2006, 02:30 PM

Quote:

Originally Posted by jdm8thgen

just upgrade the rear sway bar with the si one. adding the front too will just make the car push more in the turns rather than rotate.

Do you have an Si, if so - do you feel that understeer is a problem?

An EX front sway with an Si rear would be too mismatched I feel, and iVTEC has confirmed this in his writeup.

Si Front & Rear Sways on an EX Sedan

DumbasSi · 06-26-2006, 03:05 PM

Great write up. I've found that upgrading the wheel/tire combination to an Si wheel/tire set-up improves the handling even more without sacrificing the ride quality one bit.

I think the bigger Si rear bar would lessen the understeer that is common with the FWD platform. The Si sway isn't that much bigger then the EX one.

jdm8thgen · 06-26-2006, 04:40 PM

Quote:

Originally Posted by DumbasSi

Great write up. I've found that upgrading the wheel/tire combination to an Si wheel/tire set-up improves the handling even more without sacrificing the ride quality one bit.

I think the bigger Si rear bar would lessen the understeer that is common with the FWD platform. The Si sway isn't that much bigger then the EX one.

it's 6mm bigger. which is decent. the upgrade for the si that companies are doing is 4-5mm. so i think a 6mm thicker rear sway for the ex is gonna yield a big improvement. and to answer your question i dont have my car yet. it comes in late july. damn the wait for navi ex's. lol

iVTEC · 06-26-2006, 08:53 PM

Quote:

Originally Posted by jdm8thgen

just upgrade the rear sway bar with the si one. adding the front too will just make the car push more in the turns rather than rotate.

I have both the Si front and rear sways in my EX sedan. In theory, yes at the limit the car will understeer more with the Si front and rear sways versus with just the rear sway.

I guess it comes down to what you're looking for. I personally wanted a car that didn't wander (that vague feeling that the thread starter described), stayed flat in the turns, and gave me a feeling of confidence and connectedness to the road. I don't auto-x or race. I do enjoy curvy country roads and taking sweeping freeway on/off ramps at 20+mph over the stated speed limit. Sorry, just the rear Si bar didn't do the trick for me. I didn't get that feeling until I put both the Si front and rear sways in.

Now the thought of the 22mm Progress rear and the Si front... now that sounds appealing. But that will have to wait until later. No $$$ for that at the moment, plus I'm loving the car as-is.

Good luck whatever you decide to do.

iVTEC · 06-26-2006, 09:03 PM

Quote:

Originally Posted by gbae007

This is a good suggestion - I was thinking of sways before the springs, anyway.

Regarding the tires, 225 would not safely fit on a 6.5 inch wide rim. (That's the EX 16" rim size.)

Yes, 225's will bulge a bit on the 6.5 inch wide 16" rims. I've read some authors who are strongly opposed to mounting 225's on 6.5" wide rims for that reason. However, I put some Goodyear Eagle F1 Gs-D3's on my old RSX-S with the stock 16 x 6.5" rims. They worked fine and I never had any problems. Per the TireRack.com website, 6.5 was the minimum rim width for the 225 tire size, so I just went with it and not once did I regret my decision.

This would be a truly stealth mod.

Good luck.

iVTEC · 06-26-2006, 09:13 PM

Another random thought. I think some members of this forum are selling their Si suspensions. You might consider getting one for an OEM upgrade. Do a write-up so that we can all benefit from the experience. Add to collective body of knowledge and all that.

I don't know if the aftermarket has dampers out yet. I know there are some spring sets.

jdm8thgen · 07-01-2006, 11:15 PM

Quote:

Originally Posted by iVTEC

I have both the Si front and rear sways in my EX sedan. In theory, yes at the limit the car will understeer more with the Si front and rear sways versus with just the rear sway.

I guess it comes down to what you're looking for. I personally wanted a car that didn't wander (that vague feeling that the thread starter described), stayed flat in the turns, and gave me a feeling of confidence and connectedness to the road. I don't auto-x or race. I do enjoy curvy country roads and taking sweeping freeway on/off ramps at 20+mph over the stated speed limit. Sorry, just the rear Si bar didn't do the trick for me. I didn't get that feeling until I put both the Si front and rear sways in.

Now the thought of the 22mm Progress rear and the Si front... now that sounds appealing. But that will have to wait until later. No $$$ for that at the moment, plus I'm loving the car as-is.

Good luck whatever you decide to do.

u wanting the progress rear sway only to upgrade ur si swayn is the same as an si owner upgrading his/her rear sway only. exactly like when i upgrade mine with just the rear si. ur in reality doing the same thing. exactly what im telling this guy. dont waste money on si front sway. itll cause more push than he has now. just do hfp wheels and si rear swaybar.

06-25-2006, 02:32 AM	#1 (permalink)
gbae007 Senior Member Join Date: Jun 2006 Location: Portland, Oregon Age: 27 Posts: 881 iTrader: 0 / 0%	Performance Dynamics Reviewed: EX Coupe It has been about a month now that I've had the new EX Coupe 5MT. To preface, I'm not a tracking-going driver but I'm an avid "driving enthusiast" and consider myself a strong driver on the backroad twisties. I've been taking weekend drives to get more intimate with the EX's handling, braking and road holding dynamics and this is a review of those areas, based on my experiences within the past 4 weeks. UNDERSTEER Driving a front-drive car, understeer is always a big consideration. Fortunately, it is easily tempered by judicious use of the throttle and is a surprise given the front-biased weight distribution. (60/40; FR/RR). Understeer gets more apparent at low speed, sharper turns than say, a high-speed sweeper. I wouldn't go far as saying that I can induce meaninful oversteer midcorner, but I have been able to rotate the car via left-foot braking and lift-throttle yaw at speed. I haven't driven the Si, but I know that the spring rates, damping rates and roll-rate is increased relative to the EX (which in-turn, is more aggressive than the Civic Sedan.) In particular, based on Shawn Church's review from TOV, the Si's rear roll-bar has a relative 4xx% increase in stiffness than the EX. Still, I'm surprised than the EX handles and communicates road-feedback as with as it does, despite these setbacks. HANDLING DYNAMICS The stock configuration is more set up for a balance of comfort and performance than aggressive driving. The car simply does not like rapid direction changes. There is too much body roll, the rear starts to feel unsettled in a slalom situation and there is too much brake dive & acceleration sqaut. I appreciate the ground clearance but I would gladly trade 1 to 1.5 inches of that to address the areas above. The upside is that the low weight of the car allows you to "throw" the car into a corner at speeds faster than the laws of physics prescribe, only to pull out of a four-wheeled drift with some throttle-action. BRAKES Surprisingly capable. The have a sensitive initial bite and becomes easier to modulate after that initial bite. Strong braking throughout but noticeable brake fade exists in high-speed and downhill driving. At one point, I was driving on a road which twists downhill for about 5 miles and ends in a 100+ mph straight stretch. At the end of the run which concludes with a 100 - 0 mph run, I got out of my car to find the front brakes growing bright red. Most research I've done suggests that rotor surfaces must exceed 1300 deg F for this to happen. On the bright side, despite the fade that occasionally creeps up in intense driving conditions, the brake pressure on the pedal remains consistant even when the rotors are operating at temperatures that should boil the brake fluid over. THE NEXT STEP I feel like I have a good idea of how the car handles - enough to starting thinking about addressing the dynamic weaknesses of the car. They are as follows: [sway-bars] Much stiffer roll-bars, especially in the rear. I hope to drive drive an Si for reference and if that doesn't prove to be aggressive enough (I suspect not,) then I will look to the aftermarket. I have only seen the Progress rear sway to date, and I wouldn't get that unless I had a front sway to keep that balance in check. The Progress rear sway is even stiffer than the Si's. [dampers] More than anything else, the dampers are the performance bottleneck in the EX suspension system. They are simply under-damped because the OEM emphasis is on comfort and not performance. The result is vagueness and sluggish manners. It also creates the sensation of floating, and not a firm contact with the road. [springs] I wish I knew the spring rates for all of the springs out there in the aftermarket for the EX coupe. Most times, manufacturers just list the drop in height. This is good if you want it just for look, but I know that spring rates can really define how the car feels. I need the numbers! Anyway, once I do more reseach, I want to lower the car 1.0 to 1.5 inches to allow the use of a stiff spring rate. That's it for now. This review isn't so much of a review, but me thinking out loud and getting my thoughts on paper, er the web. Feel free to comment or ask question if you have them. Last edited by gbae007; 06-25-2006 at 02:41 AM.

06-25-2006, 04:33 PM	#2 (permalink)
webby Acorns! Join Date: May 2005 Location: Storage Room B Posts: 13,378 iTrader: 11 / 100%	wow that's a nice write up. Do you ever get into autox stuff at all? If you've never taken a stab at it, you may really enjoy doing some at some meets/weekend get togethers. As far as brake fade - I know a few members have already updated their pads to hawk or other brands which they said had a significant improvement in performance and brake fade issues. - less brake dust as well with some brands. the spring rates can be seen below as far as helping you out a bit. SI spring rates: Front 200 lbs. / inch Rear 230 lbs. / inch This means that the DX, LX, and EX Coupe rates are approximately: Front 170~175 lbs. / inch Rear 200 ~ 205 lbs. / inch This is taking into account the Si front rates are listed by Honda as being 17-18% stiffer and the rears are 14-15% stiffer than regular Coupes. And obviously there is the ability to swap out the SI sway bars as well which are much thicker. again - nice writeup.

06-25-2006, 05:42 PM	#3 (permalink)
aodmisery Senior Member Join Date: Nov 2005 Location: Norcal Age: 27 Posts: 1,693 MEOW!! iTrader: 1 / 100%	dont know if your interested or if it fits on an ex but i got the stock si's suspension for sale 200 plus shipping. P.s. this is my 100th post!! so what do i win!!

06-26-2006, 12:56 AM	#8 (permalink)
kenchan Senior Member Join Date: Apr 2006 Location: Midwest Posts: 2,281 iTrader: 1 / 100%	i have a sedan, but i can surely agree to the 'floating' feeling you described. the rear toe is set too mildly as if it's already at zero toe for tire wear and fuel economy reasons... the rear wanders a tad when one side of the car goes over a bump. this unsettling feel was apparent on not only my EX sedan, but on other 06 civics. When i do finally lower the ride down the road, i would set the rear toe to about 0.10 to 0.12 degrees each side. this should minimize the rear floating/shifting feel. anyone know the factory rear toe setting? thanks.

06-26-2006, 01:31 AM	#9 (permalink)
iVTEC Senior Member Join Date: Nov 2005 Location: NBA Kings Courtside Posts: 411 iTrader: 0 / 0%	I'd recommend purchasing 17" wheels with 215/45-17 tires and the Si front and rear sway bars before doing anything with the springs. It might just give you what you're looking for without having to sacrifice too much ride comfort by going with stiffer springs. The vagueness that you attribute to the dampers can also be caused by the flexible tire sidewalls and the relatively flimsy sway bars. Check this out: Si Front & Rear Sways on an EX Sedan

06-26-2006, 02:04 AM	#10 (permalink)
iVTEC Senior Member Join Date: Nov 2005 Location: NBA Kings Courtside Posts: 411 iTrader: 0 / 0%	Or instead of upsizing the wheel size, you might consider just getting wider, lower profile tires (225/50-16) and keeping the stock rims. You might run into problems with the sidewalls bulging out though, since the stock rims are only six or six and a half inches wide.

06-26-2006, 01:39 PM	#12 (permalink)
GlennS Senior Member Join Date: Apr 2006 Location: Connecticut Age: 54 Posts: 574 iTrader: 0 / 0%	Okay, I've got a question that I can't find an answer to: What are the HFP springs and dampers rated at? There are HFP kits ($600 at College Hills) for the Si, the coupe and the sedan. I've got a sedan, and I'm wondering how stiff (harsher ride) the HFP springs and dampers would be? Sounds like an Si rear roll bar on the sedan would be a good move. Si Front & Rear Sways on an EX Sedan

06-26-2006, 03:05 PM	#15 (permalink)
DumbasSi Senior Member Join Date: Aug 2005 Location: Ontario, Canada Posts: 1,580 iTrader: 4 / 100%	Great write up. I've found that upgrading the wheel/tire combination to an Si wheel/tire set-up improves the handling even more without sacrificing the ride quality one bit. I think the bigger Si rear bar would lessen the understeer that is common with the FWD platform. The Si sway isn't that much bigger then the EX one.

06-26-2006, 09:13 PM	#19 (permalink)
iVTEC Senior Member Join Date: Nov 2005 Location: NBA Kings Courtside Posts: 411 iTrader: 0 / 0%	Another random thought. I think some members of this forum are selling their Si suspensions. You might consider getting one for an OEM upgrade. Do a write-up so that we can all benefit from the experience. Add to collective body of knowledge and all that. I don't know if the aftermarket has dampers out yet. I know there are some spring sets.